Check whether there is a prefix binary code whose codewords lengths are exactly the provided numbers. Justify your yes or no answer, in case of affirmative answer construct a code with the speficied requirements (using Kraft's Threorem)

My first step would be check if 2^-(12) + 2^-(2) + 2^-(1) <= 1 according to Kraft's inequality then I'm stuck at the part turning them into set of prefix code, something like C = { prefix code 1, prefix code 2, prefix code 3}...